document.write( "Question 437478: TriangleABC is an acute triangle. Two of its side measure 11cm and 14cm. What is the rangle of possible values for its third side? \n" ); document.write( "
Algebra.Com's Answer #302682 by richard1234(7193)\"\" \"About 
You can put this solution on YOUR website!
A corollary from the law of cosines, a triangle with sides a,b,c is acute if and only if \"a%5E2+%2B+b%5E2+%3E+c%5E2\" (this inequality is also symmetric, so it applies if you switch the ordering of a,b,c). Hence, for a triangle with sides 11, 14, and x, all three inequalities must be satisfied:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"11%5E2+%2B+14%5E2+%3E+x%5E2\" --> \"x+%3C+sqrt%28317%29\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"11%5E2+%2B+x%5E2+%3E+14%5E2\" --> \"x+%3E+sqrt%2875%29+=+5sqrt%283%29\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"14%5E2+%2B+x%5E2+%3E+11%5E2\" --> all values x satisfy this inequality.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "From the first inequality, the solution set for x is (\"-infinity\", \"sqrt%28317%29\") and from the second inequality, the solution set is (\"5sqrt%283%29\", \"infinity\"). Taking the intersection of these sets, the only possible values for x are those lying in the set (\"5sqrt%283%29\", \"sqrt%28317%29\").\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "
\n" );